Abstract: A logical volume manager (LVM) may manage a plurality of logical volumes and a plurality of drives in a logical data storage using metadata stored on the plurality of drives. The LVM may operate in one of two modes. In the first mode, the LVM may deleted uncommitted metadata on a drive and may use committed metadata on the drive when accessing a logical volume. In a second mode, the LVM may use committed metadata on the drive when accessing the logical volume and may refrain from deleting the uncommitted metadata.

Abstract: A logical volume manager (LVM) may manage a plurality of logical volumes and a plurality of drives in a logical data storage using metadata stored on the plurality of drives. The LVM may operate in one of two modes. In the first mode, the LVM may deleted uncommitted metadata on a drive and may use committed metadata on the drive when accessing a logical volume. In a second mode, the LVM may use committed metadata on the drive when accessing the logical volume and may refrain from deleting the uncommitted metadata.

Abstract: An exemplary system may allow new devices to be added. In one embodiment, upon receiving information associated with a device event, the system generates a first rule for a device based on the information and a system state. The system determines determine an updated system state based on the first rule. The system determines whether a second rule is required for the updated system state. Upon determining that the second rule is required for the updated system state, the system generates the second rule.

Abstract: An exemplary system may automatically discovery externally added devices. In one embodiment, the system obtains initial device information for a virtual machine running on a host computing system. The system determines whether an external event occurred on the host computing system. A management computing system associated with the host computing system does not receive notification of the external event. Upon determining that the external event occurred on the host computing system, the system obtains updated device information for the virtual machine running on the host computing system.

Abstract: An exemplary system may allow concurrent access to a device by different virtual machines. In one embodiment, the system receives a request to add a virtual machine (VM) of a plurality of virtual machines to a host, the request identifying a device that is shared by the plurality of virtual machines. The system creates a VM-specific rule for the device based on the VM. The system stores the VM-specific rule for the device in association with the VM.

Abstract: A computing device receives a request from a host for a shared lock on a resource. The computing device obtains an exclusive lock on the resource using a locking data structure that is stored on the storage domain. The computing device subsequently obtains a shared lock on the resource for the host by writing a flag to the locking data structure, wherein the flag indicates that the host has the shared lock on the resource. The computing device then releases the exclusive lock on the resource.